Written By Gopal Krishna on Friday, July 25, 2008 | 8:13 AM

Environmental impacts of nuclear energy generation has to be considered for the whole fuel cycle, from the mining of Uranium to provide fuel for nuclear reactors, to the disposal of radioactive wastes and the decommissioning of nuclear energy plants.

A fuel cycle is the whole sequence of processes from the energy source to the actual energy from which is transmitted/transported, and beyond the latter to the disposal/recycling of wastes and by-products. The principal environmental impacts arise through (a) radiation (b) thermal pollution. The radiation, which includes alpha, beta and gamma rays, can have adverse effects on those who are exposed to it.

Uranium is mined as uranium ore. Uranium ores are generally mined by underground or surface mining. Uranium-238 is radioactive and decays to give radon-222. Uranium milling operations lead to release of radioactive material as well as radioactive liquid wastes and tailings. Though there are many types of reactors, the primarily used reactor is the light-water reactor.

So far, no satisfactory acceptable long-term solution to high-level waste disposal problem has been developed.

The most serious environmental impact of a nuclear reactor is the loss of coolant accident (LOCA). To prevent this, reactors incorporate an Emergency Core Cooling System (ECCS).